The Promise: "The XRS 9950 provides total protection and peace of mind with Xtreme Range Superhetrodyne Technology, detecting all 12 radar/laser bands with its super-fast lock-on detection circuitry." It also has an integrated digital compass, as well as a car battery voltage display. When hooked up to its GPS locator, the XRS 9950 can deliver alerts about red light-running and speed-enforcing cameras. Cobra claims it maintains the only verified red-light camera database for the United States. Needless to say, that got us pretty excited earlier this year at CES—about the whole Big Brother thing, and a big year for new GPS units.

In Practice: First, let me state that all radar detectors use "superhetrodyne" technology, just in case anyone thought that might be something special. The extreme range part of the description is no joke—this detector picked up signals from police many miles before I ever saw them. It also picked up a lot of non-police noise that was probably from alarm systems, radar-based traffic monitoring systems, automatic opening sensors and other mysterious sources. Which is pretty much the problem with all radar detectors these days: The signal-to-noise ratio errs heavily in favor of noise. In fact, I counted what I considered to be 20 false positives for every actual radar trap the XRS 9950 picked up. It's possible that all those cops were out there hiding very, very well, but I doubt it. That's not the fault of this particular detector—it just so happens that the X and Ka bands are pretty crowded these days.

As for the GPS locator, it's a rather unwieldy thing (2.25 in. x 2.25 in. x 0.5 in.) that dangles from the main detector unit via a USB cord, though the company promises a smaller one for 2009. It works as advertised, blurting out a voice warning whenever red-light or speed-enforcing cameras are in your path. In my (rather suburban) area, I didn't come across any speed trap cameras—only cameras that would send you a ticket if you ran a red light. At every such warning, I looked around the intersection and, sure enough, there was the camera. Since I didn't plan to run any red lights, the main way Cobra's clever-seeming gadget changed my driving habits was that it made me stop looking at traffic signals and start looking for cameras instead.

Bottom Line: The Cobra XRS 9950 radar detector does indeed pick up cops with radar and laser speed detection guns and, when outfitted with the GPS accessory, automated traffic cameras. I must admit, however, that I found the camera detector accessory frustrating: There is a certain libertarian satisfaction in knowing when you're being watched, but also a certain frustration in not being able to do anything about it. —Glenn Derene